It enables
1. ml name completion via `(c-&)' and `(c-a)(c-&)'
2. fancy lambda- insertion for ml via `{la\\}'
3. fancy in-place evaluation via `{(m-z)(cm-z)}'
4. locating definitions of identifiers in structured ML objects via `show' and `(cm-(mouseright))' IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html